1. Field of the Invention
The present invention relates to rehabilitative devices. More specifically, the invention relates to a portable device for enhancing motor function in paretic extremities, such as the hands of a stroke victim.
2. Technology in the Field of the Invention
Many individuals in the United States suffer from limited motor function in their extremities. This may be due to any of several causes. Some individuals may, for example, have suffered a stroke. The term “stroke” is a lay term that typically refers to a condition wherein the blood supply to an area of the brain is temporarily cut off. This is referred to as an “ischemic stroke.”
In an ischemic stroke, a clot interrupts blood flow to a part of the brain. When blood fails to get through the brain, the oxygen supply to the affected area is cut of, causing brain cells to die. The longer the brain is without blood, the more severe the damage will be. Where the portion of the brain that controls movement of the upper extremities is damaged, the individual may be left in a state of partial paralysis, or paresis.
Some strokes are referred to as “hemorrhagic.” A hemorrhagic stroke occurs when a blood vessel in the brain itself ruptures. This produces bleeding into the brain matter, causing damage to surrounding brain cells.
Regardless of the type, stroke is the most common cause of disability in the United States. There are approximately 650,000 new and 180,000 recurrent strokes each year in the United States. About a quarter of stroke survivors are considered permanently disabled. Stroke patient rehabilitation is a billion dollar industry in the United States.
Individuals may also lose function in one or more extremities as a result of an injury. Such injuries may occur due to a car accident, a diving accident, a fall, or other trauma. In these instances, the individual's cervical spine and nerves may be injured, again producing paresis in the hands. Additionally, such trauma can produce brain injury.
In addition to these events, some individuals may develop partial upper paralysis as a result of a medical condition. Examples of such conditions include amyotrophic lateral sclerosis (ALS), hypokalemic periodic paralysis, cerebral palsy, or other diseases. Finally, some individuals may suffer some degree of paresis due to brain injury caused by an explosion or accident incident to work or military duty.
When any of these conditions of partial paralysis occur, the individual is left with limited motor function in their arms. The most common disability among the numerous stroke survivors is weakness of the hand. Such individuals have difficulty performing routine tasks such as eating, turning off a light, manipulating a remote control, typing, or countless other activities that most people take for granted.
In many instances, individuals with limited motor function will undergo therapy. Such therapy may take place at a rehabilitation facility or at a medical office. Some patients undergo expensive rehab through the use of so-called robots. Such therapy tends to be expensive. In other instances, a daily regimen of home-based rehabilitation is prescribed to achieve hand and finger functional recovery. However, home-based programs are sometimes limited by the motivation of the patient and the patient's desire or ability to use proper techniques.
Therefore, a need exists for a hand rehabilitation device that will efficiently improve hand function in stroke patients and injury victims at home or other remote location. Further, a need exists for a home-based device that provides somatosensory, or touch-based, signals as functional guidance during rehabilitation. Still further, a need exists for a portable device that does not rely upon percutaneous electrical stimulation or implant and that engages the patient's brain.